Process of treating molten iron.



. N9. 721,282. PATENTED 32112451903.

HLisUDBRUs.

I `PRCKIESS 0F TRETING MOLTEN IRON. l APPLICATION PILYL'D: FEB. 25,1902'.

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UNITED STATES Y PATENT OFFICE.

HUGO B'UDERUS, OF HIR-ZENHAIN, GERMANY.

PROOCESS OF TREATING MOLTEN IRON.

SPECIFICATION forming' part of Letters Patent N0. 721,282, datedFebruary 24, 1903. Application filed February 25, 1902. Serial No.95,589. (No specimens.)

To all whom it may concern:

Be it known that I, HUGO BAUDERUSA, a subject of the German Emperor, anda resident'of Hirzenhain, Germany, (whose postal address is Hirzenhain,Oberhessen, Germany,).have

invented certain new and useful Improvements in Processes of TreatingMoltenfIron,-

of which the following is a specification.

It is well known that when raw iron as it Io comes from theblast-furnace is used for theV production of castings the quality ofthe'iron is rimproved by mixing it with other ironsuch, for example, asiron from a cupola. (See Ledebuhrs Eisenhitttcnlcunde, 1893, Vol.

I5 II, pages 632 and 633.) It has hitherto been usual to allow the ironfrom the blast-furnace and the iron from the cupola to run into amixing-chamber, wherein both metals are intimately mixed together, themixturefbeing zo afterward run into the casting mold or molds.

- In carrying out these operationsit. has been found difficult to securein the mixture ofthe ity and constitutions of the cupola-iron to beadded, and there isnot time to make tests for 3o the purpose ofascertainingthe quality of the blast-furnace iron and of the mixture,because on account of the time occupied by such tests the temperature ofthe mixture becomes so low during the taking of the tests thatsatisfactory casting is prevented. To obviate this disadvantage,'mixing-chambers have been used in which furnaces are provided forkeeping the mixture hot. (See German Patents Nos. 50,250 and 63,727.) Ithas been,

4o however, impossible in these arrangements to avoid conditions whichseriously interfered with the practical carrying out of the process, andthe external firing is a considerable additional expense. -v Myinvention remedies these disadvantages by enabling the founder toregulate with ease and with the smallest possible consumption of fuelthe mixture formed by the iron run from the blast-furnace and that runfrom the cupola or likefur- 5o nace, as the founder can take samples andadd iron or other materials to the mixture without the heat of themixture lessening so as to interfere with the casting operation or themixture being affected by the action of the furnacefires or otherexternal causes.

Accordingto my invention I construct in front of the blast-furnace andthe cupola or like furnace a mixing-chamber inthe form of areverberatoyfurnacein which the mixture is constantly kept at thetemperature most suitable for'casting, whatever time the takingofzsampliug vtests and the mixing operations occupy. A suitablequantityof liquid slagrfrom the; blast-furnace is run into the said chambereither direct from the blastfurnace or by means' of portable ladles, sothat the said chamber is thereby efficiently preheated, and onto thisincandescent slag gaseous, liquid, or pulverulent fuel isintroduced,.and'this ignites by contact with the said incandescentslag,so thatin a very short time the chamber is raised toa high temperatureor Vwelding heat, and this high `temperature is maintained. by continuedsupply of such fuel to the said chamber. The iron fromtheblast-furnaceand that from the cupola or like furnace' are then runinto the chamber so heated and will immediately sink below the moltenslag, the latter floating on the molten iron, and as the fuel will beconstantly supplied to the chamber the iron mixture therein will be keptat the temperature required for casting and is at the same timeprotected from injurious action of the re by the aforesaid floatingslag. The founder has under these conditions sufficient time to takesamples from the mixture, and, according to requirements, he can allowmore iron to run out from the blast-furnace, as from the cupola or likefurnace, into the .mixing-chamber or he can introduce directly into thesaid chamber and melt therein other additional materials. lnthis mannerthe founder can manufacture iron of a composition fully meeting hisrequirements and proceed to the casting operation as he requireswithoutregard to the time the testing and mixing operations occupy.

A suitable mixing apparatus to carry my invention into effect isillustrated in the accompanyingdrawings, in which- Figure 1 is avertical longitudinal section ICO on the line l l of Fig. 2 or Fig. 3.Fig. 2 is a horizontal Section, and Fig. 3 is a vertical transversesection on the line 3 3 of Fig. l.

The mixing-chamber is indicated by a, and b is the opening through whichthe slag, iron, &c., is introduced onto a bridge c, whence it flows intothe mixing-chamber.

f is a nozzle through which liquid, gaseous, or pulverulent fuel isintroduced into the chamber a, and d is a tap-hole leading to a spout e.

The upper part g of the mixing apparatus is removable and is connectedto the lower part g by angle-bars h and pins or bolts t'.

The mixing apparatus is pivotally mounted at its discharge end in thebearings Z by means of the pivots 7c, and the other end may be elevatedby means of the screw m.

The hereinbefore-described addition of liquid slag has besides theabsolute protection it affords to the mixture also the great advantagethat it eiects a large saving of fuel, for the high temperature of theslag introduced does away with the necessity for preheating themixing-chamber by a special furnace, as would be the case if no slagwere run into the said chamber. The said chamber m-ay be stationary orbe made transportable, and it can, if desired, be so constructed as tohave an oscillatory motion imparted to it to assist the mixing.

The process according to my invention is especially adapted for thecheap and easy manufacture of heavy castings from iron tapped directfrom the blast-furnace and cu. pola or like furnace, for by means ofthis process it is possible to prepare from blastfurnace iron largequantities of a mixture of different descriptions of iron suitable forcasting purposes by making the mixing-chamber of large dimensions or byerecting several chambers in front of both blast-furnace and cupolaorlike furnace, the latter plan being no obstacle to the obtain ment ofa uniform product, as with this improved process it is always possibleto render uniform'the charges in the whole of the mixing-chamber.

I claim- Y The process herein described of improving the quality ofmolten iron from blast-furnaces for the production of castings andmaintaining it at the temperature required for casting, which consistsof rst introducing molten slag into a mixing-chamber, then introducingfuel therein above the molten slag to raise the temperature of saidchamber and maintain the slag in a molten condition, then introducingthe molten iron from the blast-furnace, and, during the continuedintroduction of fuel above the molten slag, introducing and mixing withthe molten iron material necessary to improve its quality, and finallyconveying the molten iron from the chamber to molds to form castings,substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

HUGO BUDERUS.

Witnesses:

FRANZ HAssLAcHER, MICHAEL VOLK.

